I think I have enough ideas to go on with, but the thread may be helpful to others.
Thank you all for your suggestions.
I'm having a job trying to put (mobi) books I've had sent to me via email on the kindle
It was dead simple to add them to my desktop kindle, just drag and drop, but I don't like reading from there, much prefer to sit in a comfy chair with the kindle.
Then I had forgotten I also have a lot of Lee Childs books on the desk top, but I want them on the kindle.
TheLee Childs books are epub and they need to be converted to mobi
Itīs all too much for my old brain.
I need calibre it says so I downloaded calibre, then have no idea how to carry on, so I opened my old Samsung, perhaps itīs easier on windows I thought,--- oh bu**er I forget how the windows work, haven't touched it for months and all my windows knowledge has gone out the window.
I give up for today, busy tomorrow and Wednesday maybe have another try on Thursday.